The invention relates to a method for making a molten film of metal, in particular a steel film, more uniform, and to a device for carrying out the method.
The invention can be employed wherever a molten film of metal, in particular of steel, is applied to a substrate, in particular to a revolving conveyor belt, in molten form and its thickness and properties are to be as uniform as possible over the width of the strip.
During the strip casting of metal, in particular of steel, the cast thickness of the strip can to a large extent be selected optimally according to the required thickness during finish rolling and for the necessary hot forming to achieve sufficient materials properties. It is known to cool the molten metal using suitable methods and devices in such a way that the surface of the liquid strand of metal is cooled uniformly by contact with an inert gas.
DE 44 07 873 C2 describes a method and a device for cooling molten steel, in which nozzles are directed onto the surface of the steel strand at an angle of between 0 and 50° in the direction of casting, with the result that the steel surface is cooled uniformly and in a controlled manner. This makes it possible to avoid any scaling and to achieve controlled dissipation of heat, with the result that the surface tension is influenced in a controlled way and the desired quality of the steel strand or steel strip is achieved. However, a constant thickness also remains important to the quality of a strip made from steel with a view to achieving uniform materials properties over the width of the strip, and this cannot readily be achieved simply by applying the molten steel to the conveyor belt.
Therefore, the object of the invention is to improve the prior art in such a way that it becomes possible to alter a film of molten metal before and after it comes into contact with the conveyor belt, so that it has a uniform thickness with uniform materials properties over its width.